Intel Core i7 6950X Advantages
Larger memory bandwidth (76.8GB/s vs 41.6GB/s)
Higher base frequency (3.0GHz vs 2.9GHz)
Larger L3 cache size (25MB vs 9MB)
Intel Core i5 9400F Advantages
Released 2 years and 8 months late
Higher specification of memory (2666 vs 2133)
Lower TDP (65W vs 140W)